<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="./jquery-1.11.3.js"></script>
</head>
<body>
    <h1>一级标题</h1>
    <input type="radio" name="" value="male" checked>
    <script>
            $('h1').attr('id','d1');
            $('h1').prop('class','c1');
            console.log($('input').attr('checked'))
            console.log($('input').prop('checked'))
 
            $('h1').removeAttr('id');
    </script>
</body>
</html>